The rib cage helps push air out of the lungs as well. Muscles lining the rib cage help move the rib cage up upon inhalation, so the lungs can expand. During exhalation, the muscles and the lungs relax, allowing the weight of the rib cage to push out carbon dioxide air through the mouth and nose.

Although the rib cage works to protect delicate organs, it is also fragile. People break or fracture their ribs on a regular basis.